added test for the fix

Signed-off-by: Lev Zemlyanov <lev@confluent.io>

Author: Lev Zemlyanov

src/test/java/io/confluent/connect/elasticsearch/jest/JestElasticsearchClientTest.java

@@ -36,6 +36,7 @@
 import io.searchbox.indices.IndicesExists;
 import io.searchbox.indices.mapping.GetMapping;
 import io.searchbox.indices.mapping.PutMapping;
+import java.util.Collections;
 import org.apache.kafka.connect.data.Schema;
 import org.apache.kafka.connect.errors.ConnectException;
 import org.junit.Before;
@@ -56,6 +57,7 @@
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.when;
 
 public class JestElasticsearchClientTest {
@@ -89,6 +91,23 @@ public void getsVersion() {
     assertThat(client.getVersion(), is(equalTo(ElasticsearchClient.Version.ES_V1)));
   }
 
+  @Test
+  public void attemptToCreateExistingIndex() throws Exception {
+    JestElasticsearchClient client = new JestElasticsearchClient(jestClient);
+    JestResult success = new JestResult(new Gson());
+    success.setSucceeded(true);
+    IndicesExists indicesExists = new IndicesExists.Builder(INDEX).build();
+    when(jestClient.execute(indicesExists)).thenReturn(success);
+    when(jestClient.execute(argThat(isCreateIndexForTestIndex()))).thenReturn(success);
+
+    client.createIndices(Collections.singleton(INDEX));
+    InOrder inOrder = inOrder(jestClient);
+    inOrder.verify(jestClient).execute(info);
+    inOrder.verify(jestClient).execute(indicesExists);
+
+    verifyNoMoreInteractions(jestClient);
+  }
+
   @Test
   public void createsIndices() throws Exception {
     JestElasticsearchClient client = new JestElasticsearchClient(jestClient);